Dragline bucket for moving slurry-type material

ABSTRACT

A dragline bucket having a lip for moving slurry-type material, a lip for a dragline bucket, a retrofit kit for a dragline bucket and associated methods are described.

RELATED APPLICATIONS

This application claims the benefit of U.S. Application No. 63/153,378, entitled “Dragline Bucket For Moving Slurry-Type Material,” and filed on Feb. 25, 2021, which is incorporated herein by reference in its entirety.

FIELD

Some implementations relate generally to dragline buckets, and, more particularly, to a dragline bucket for moving slurry-type material.

BACKGROUND

Draglines are mining machines used in surfaces mines to move dirt. The most prolific use of these machines is in coal mines where the layers of dirt on top of, and in between, coal seams are removed by the dragline after which other machines, like hydraulic shovels, rope shovels and wheel loaders are used to dig and load the coal. The layer of earth (dirt) above the first coal seam (or other type of seam or material being mined) is called overburden and the layers of dirt in between subsequent coal seams are called the interburden.

Draglines are relatively cheap to use in terms of the energy utilized to move one cubic yard of dirt. The ratio of the thickness of the overburden in a surface coal mine defines the strip ratio and usually dictates the use, or not, of a dragline. In certain instances of low strip ratios, the use of draglines is not economical and other machines, like hydraulic or rope shovels, are used, not only to load the coal but also to remove the overburden. The overburden/interburden in coal mines are usually dry, often very blocky, and sometimes with large layers of stone. For this reason, the dirt is mostly blasted with explosives to break it up into a well-defined and dig-able refined state.

In phosphate surface mines, the strip ratio is very small, and draglines are used not only to remove the earth above the matrix, or mined product, but also to load the matrix itself into a well or enclosed earthen dam, from where the matrix is pumped to the production facility. In this application, the dirt above the matrix is soft and therefore not blasted. The water table is also very high which results in the dragline bucket mostly moving a slurry-type material, very much different from the dry, broken up dirt being moved in a coal mine application.

A typical dragline is a mining machine consisting of a long boom, angled about 40° to the horizontal, attached to the front of a rotating machinery house, which in turn can move with typical caterpillar tracks, or with specially designed feet. A dragline bucket is attached to two sets of wire ropes, each of which is coiled over a large motorized, rotating drum. Rotating these drums causes the length of the extended ropes to change. One set of wire ropes extends horizontally outwards from the machinery house and is used to drag the bucket through the dirt or soil in order to fill the bucket. The second set of wire ropes runs along the boom over provided sheaves and is used to hoist the bucket after it is filled. The filling action is called “drag” and the hoisting action is called “hoist”, with the applicable wire ropes therefore called “drag ropes” and “hoist ropes” respectively. The set of hoist ropes, as well as the set of drag ropes, can consist of anything from a single rope to up to four parallel ropes.

A typical dragline operating cycle is defined by four phases and bucket parameters are at play in each phase of the operating cycle which determine the efficiency of the bucket. The first phase is spotting, which is the action by the dragline operator of swinging and placing the bucket at the point of intended digging. The second phase is to drag the bucket through the dirt (or slurry-type material) until it is filled with dirt. The third phase is to lift and hoist the bucket to a height where it is clear of the surrounding earthen cuts and heaps and swing the bucket to the location where the dirt will be placed in a heap at a specific location. The fourth phase is to dump the bucket so that the dirt (or other material) exits from the bucket at the desired dump location. The operating cycle then moves back into the first phase of spotting or swinging and lowering the bucket to the intended dig location.

The drag phase is further divided into three key events or sub-stages. The first sub-stage is an “engage” event where the bucket digs into the dirt and allows the dirt to start flowing toward the rear of the basket within the bucket. The second drag phase sub-stage is “filling” in which the dirt continuously flows into the rear of the bucket until the bucket is full, or ready to be “disengaged,” which is the last sub-stage of the drag phase where the bucket is picked up (or hoisted) and ready to be moved to the dump point.

Between the bucket and the wire ropes is a collection of steel chains and components, which makes up what is called the “dragline rigging” including hoist chains that are an extension of the hoist ropes and drag chains that are an extension of the drag ropes. In order for the bucket to move freely between the hoist chains a spreader bar is employed as a horizontal spacing member to keep the hoist chains apart and allow the bucket to pivot between them. The use of chains is to prevent wear damage to the ropes, as well as to facilitate the dump phase by allowing for a dump rope, which is a wire rope attached to the drag chains, running over a sheave and then being attached to the bucket. The dump rope connects the bucket to the drag ropes/chains via the dump sheave, and therefore influences the bucket orientation depending on the tension in the drag ropes. The dump rope holds the front of the bucket at a specific orientation to prevent spilling of the dirt from the bucket while it is being hoisted, with tension on the drag ropes, and then allows the bucket to dump, expelling the dirt, when the dump phase is initiated by relaxing the drag ropes.

In order for a dragline bucket to dig and fill efficiently the key bucket parameters need to be conducive to fast digging and filling. A typical dragline bucket consists of a large frontal opening which has, as a lower element, an angled lip plate with a number of teeth arranged with pointed parts outwards. The lip is joined at each end to the cheek plates with hitch points where the drag chains are attached. The bucket is therefore dragged by action of the drag ropes, attached, via the drag chains, to bucket hitches on respective bucket cheeks. The bucket cheek usually runs up into a curved arch, on which apex there is attached the dump rope. The combination of these three elements—lip, cheeks and arch—is called the front ring. The purpose of the front ring is to facilitate digging into the dirt, by allowing the bucket to be dragged, and move the dirt with the lip and teeth toward the rear of the basket of the bucket. The arch provides an attachment point for the dump rope with which the bucket orientation is manipulated. The rear of the bucket behind the front ring is called the basket, which in turn, is shaped to provide for the most efficient carrying of the dirt. The basket consists of the floor, rear and side walls, which are all bound together with a rim that is called the top rail. On the outside of each of the side walls is a trunnion on to which the hoist ropes are attached, via the hoist chains.

It is important to note that a dragline bucket, hanging from both the drag and the hoist ropes under the angled dragline boom, is entirely dependent for its orientation to the horizontal (earth) on the location of its own center of gravity, selection of lengths of the drag and hoist chains, the length of the dump rope, and the geometry of all other relevant rigging components. Primarily, the bucket orientation can be changed by changing the length of the dump rope if all the other parameters are maintained constant. However, during operation, the bucket orientation cannot be manipulated by the dragline operator other than by moving the drag and hoist ropes inwards or outwards. Changing the length of the hoist and drag ropes would move the bucket to any desired location underneath the boom, and the geometry of the rigging, and the geometry of the bucket itself, would determine the bucket orientation at that specific location. Hence key bucket and rigging geometry parameters would determine at what point below the dragline boom the bucket would disengage (pick up) without spilling the dirt, and at which point the bucket will dump, releasing and expending the dirt. The operator cannot decide where the bucket should be dumped other than relaxing and extending the drag ropes to a point where the dump rope will release the forward part of the bucket to dump. Similarly, the bucket cannot necessarily be disengaged at any point below the boom. The bucket can only be disengaged at a point where the tension on the drag ropes will cause the dump rope to hold the front of the bucket at an angle where no dirt will spill out the front. The setting of the geometry of the dump rope relative to other rigging elements will allow for a certain point under the boom where the bucket can be picked up without spilling the dirt out of the front—called the “disengage point.”

In order to be in control of the bucket disengage point, the length of the dump rope is set to a value which would make the bucket to hang at a specific orientation—or angle of the bucket floor to the absolute horizontal—at a specific point under the boom. Setting the dump rope length at a predefined value would result in the bucket disengaging at a specific location under the boom and would also result in the bucket carrying the dirt without spilling out the front. This angle is called the bucket “carry angle” and is any arbitrary value at any arbitrary point under the boom which can be set repeatable every time the dump rope is replaced. This technology has developed to where the bucket carry angle is defined for the empty bucket hanging just off ground level, halfway underneath the boom. A range of values for this angle is defined as effective or not.

The carry angle not only defines the disengage point but also determines how efficiently the bucket carries the dirt without spilling out the front, from the disengage point all the way until the drag ropes are relaxed, the dump rope releases tension on the front of the bucket (the arch), and the bucket pivots forward to dump the dirt out. If the bucket carry angle is set correctly the bucket will move the most amount of dirt in the shortest amount of time, in that the bucket would disengage at the soonest time after filling, would pick up the most amount of dirt without spilling, and would be able to be hoisted and swung without losing any more dirt.

When the bucket disengages in a typical coal mine application with dry, blocky overburden, the wall of dirt at the open front end of the bucket remains at a steeper angle than the natural angle of repose of the dirt because of the bucket carry angle (tilted backwards) and the compression effect of digging. The shape of the basket would therefore directly impacts how much dirt can be carried in the bucket. Dragline buckets for the coal industry have therefore followed a unique path of development where the basket shape and bucket carry angle have been optimized to carry the most amount of dirt.

However, when a bucket, which is designed for the dry coal mines, is used in a phosphate mine application where the matrix is contained in slurry and mud, the basket shape is wholly inadequate to carry an efficient amount of matrix. The phosphate industry has accepted this fact and become accustomed to the inefficient productivity of dragline buckets in their application.

Embodiments were conceived in light of the above-mentioned problems and limitations, among other things. The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor(s), to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

SUMMARY

The subject matter disclosed herein includes dragline buckets, lips, retrofit kits, and methods for making the same where the dragline buckets are constructed specifically for use in a slurry-type environment such as that found in phosphate mining and are formed to carry an optimal or nearly optimal amount of slurry or mud. When the carry angle of a bucket constructed according to the disclosed subject matter is set correctly, productivity can be enhanced significantly compared to using conventional coal mine shaped buckets in a slurry-type environment.

A traditional dragline bucket has the basket side walls and rear wall ending at a horizontal plane, parallel to the basket floor (see, for example, U.S. Pat. Nos. 4,791,738 and 8,250,785, which are incorporated herein by reference in their entirety). This has been found to be the most efficient configuration for a wide range of digging conditions, and a maximum height of the side and rear wall is the deciding factor. Consequently, typical dragline buckets have high side and rear walls relative to the width and length of the bucket. There have been several ideas which depart from this philosophy which have the side walls sloping downwards from the front ring and then back up again (see, for example, US Published Application 2009/0235560, which is incorporated herein by reference in its entirety). This idea depends on a certain low point in the bucket side walls so as to allow the dirt to flow over and out of the bucket as it is moved into the bucket and showed significant success in certain dry digging conditions.

There are two principles in operation. The first is the idea of releasing the pressure created by dirt already in the bucket which prevents more dirt from flowing over and into the rear of the bucket. By allowing dirt to escape sideways out of the bucket an easier path is created for subsequent dirt flow to the rear of the bucket. The second principle is to have as little as possible steel required to keep a heap of dirt in the bucket. By not having high side walls—essentially having a scalloped side wall—the heap of dirt in the bucket is made by the natural angle of repose of the dirt, and if the carry angle can be selected correctly a high volume of dirt can be carried in this way. The important thing is obviously to allow the dirt to flow up into a heap which is then effectively carried.

Some implementations can include a dragline bucket comprising a basket having a front ring, a rear wall, a first sidewall, a second sidewall, and a floor, wherein the first sidewall and the second sidewall each include a trunnion, and a first additional side wall and a second additional side wall extending from a top rail of the basket toward a rear end of the basket at a first angle. The dragline bucket can also include an additional rear wall portion at the rear end of the basket joining the first additional side wall and the second additional side wall, wherein the additional rear wall portion slopes forward at a second angle relative to a plane of the basket floor. The first additional side wall, second additional side wall, and the additional rear wall form a dragline bucket lip (or “soup lip”) as discussed herein.

In some implementations, the first additional side wall and the second additional side wall slope upwards from the top rail starting at points approximately above respective trunnions and extend upwards at an angle approximately between 20° and 40° relative to the floor towards the rear wall. In some implementations, the rear wall follows a first plane, and the additional rear wall portion follows a second plane different than the first plane. In some implementations, the additional rear wall portion slopes forward toward the front ring at an angle of approximately 45° to 60° relative to the floor so as to clear a rigging spreader bar. In some implementations, the additional rear wall is in the same or nearly the same plane as the basket rear wall.

In some implementations, the first side wall and the second side wall follow a third plane and the first additional side wall, and the second additional side wall follow fourth and fifth planes, respectively. In some implementations, the fourth and fifth planes are different than the third plane. In some implementations, each of the fourth and fifth planes are inclined inward towards the longitudinal center plane of the basket at an angle of approximately 50° to 80° relative to the floor.

In some implementations, the front ring includes an angled lip, and a sludge line of the dragline bucket is defined by the first angle of the first and second additional side wall portions and the angled lip. In some implementations, the sludge line forms a level line of slurry-type material inside the basket when the dragline bucket is oriented at a given angle relative to horizontal and with the bucket lip being at a same vertical height as a rear edge of the additional side and rear wall portions of the basket.

Some implementations can include a lip for a dragline bucket, the lip comprising a first side wall having a top edge angled relative to a horizontal plane including a bottom edge of the first side wall, a second side wall having a top edge angled relative to a horizontal plane including a bottom edge of the second side wall, and a rear wall joining the first side wall and the second side wall and having a top edge. The lip can further comprise a top rail disposed at and extending along at least a portion of the top edge of the first side wall, the top edge of the second side wall, and the top edge of the rear wall.

In some implementations, the rear wall slopes forward at an angle relative to the horizontal plane including the bottom edges of the first side wall and the second side wall. In some implementations, the rear wall is oriented vertically with respect to a horizontal plane including the bottom edges of the first side wall and the second side wall.

In some implementations, the lip is constructed to be retrofitted onto a non-tapered dragline bucket. In some implementations, the lip is constructed to be retrofitted onto a tapered dragline bucket. In some implementations, the lip is constructed to be formed onto a new non-tapered dragline bucket. In some implementations, the lip is constructed to be formed onto a new tapered dragline bucket.

Some implementations can include a retrofit kit for a dragline bucket, the retrofit kit comprising a lip for the dragline bucket. The lip can include a first side wall having a top edge angled relative to a horizontal plane including a bottom edge of the first side wall, a second side wall having a top edge angled relative to a horizontal plane including a bottom edge of the second side wall, and a rear wall joining the first side wall and the second side wall and having a top edge.

In some implementations, the lip can further comprise a top rail disposed at and extending along at least a portion of the top edge of the first side wall, the top edge of the second side wall, and the top edge of the rear wall. In some implementations, the rear wall slopes forward at an angle relative to the horizontal plane including the bottom edges of the first side wall and the second side wall. In some implementations, the rear wall is oriented vertically with respect to a horizontal plane including the bottom edges of the first side wall and the second side wall. In some implementations, the lip is constructed to be retrofitted onto a non-tapered dragline bucket. In some implementations, the lip is constructed to be retrofitted onto a tapered dragline bucket.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a perspective view of an example dragline bucket in accordance with some implementations.

FIG. 2 is a diagram showing a side view of an example dragline bucket in accordance with some implementations.

FIG. 3 is a diagram showing a front view of an example dragline bucket in accordance with some implementations.

FIG. 4 is a diagram showing a side view of an example dragline bucket in accordance with some implementations.

FIG. 5 is a diagram showing a front perspective view of an example angled lip on a tapered bucket in accordance with some implementations.

FIG. 6 is a diagram showing a side elevation view of an example angled lip on a tapered bucket in accordance with some implementations.

FIG. 7 is a diagram showing a front elevation view of an example angled lip on a tapered bucket in accordance with some implementations.

FIG. 8 is a diagram showing a front perspective view of an example vertical lip on a tapered bucket in accordance with some implementations.

FIG. 9 is a diagram showing a side elevation view of an example vertical lip on a tapered bucket in accordance with some implementations.

FIG. 10 is a diagram showing a front elevation view of an example vertical lip on a tapered bucket in accordance with some implementations.

FIG. 11 is a diagram showing an exploded view of an example lip and bucket in accordance with some implementations.

FIG. 12 is a diagram showing a rear perspective view of an example lip in accordance with some implementations.

FIG. 13 is a diagram showing a front perspective view of an example lip in accordance with some implementations.

FIG. 14 is a diagram showing an exploded view of an example lip and bucket in accordance with some implementations.

FIG. 15 is a diagram showing a front perspective view of an example lip in accordance with some implementations.

FIG. 16 is a diagram showing a rear perspective view of an example lip in accordance with some implementations.

FIG. 17 is a flowchart showing an example method of manufacturing a lip for slurry-type material in accordance with some implementations.

FIG. 18 is a flowchart showing an example method of manufacturing a dragline bucket including a lip for slurry-type material in accordance with some implementations.

FIG. 19 is a flowchart showing an example method of retrofitting a conventional dragline bucket with a lip for slurry-type material in accordance with some implementations.

DETAILED DESCRIPTION

Some implementations can include a dragline bucket having high side and rear walls, and which include additional side walls and an additional rear wall rear portion towards the rear of the bucket which is angled so as to provide for efficient carrying of sludge/slurry/mud when the carry angle of the bucket is set correctly.

Some implementations can include a dragline bucket configured to handle a slurry/mud/sludge type of material that does not have a natural angle of repose but would fill any hollow container while exhibiting a flat, horizontal top surface like water.

FIGS. 1-3 show an example dragline bucket with the additional side and rear wall portion (or lip or soup lip) installed on the rear of the bucket. The additional side walls and rear wall portions can be built into the bucket at manufacture time of the bucket or can be added as an upgrade to an existing bucket. The additional side walls can start at a point, for example at (1) approximately above the trunnion on each side of the basket and extend upwards at an angle (2) relative to the bucket floor. However, it will be appreciated that the starting point of the additional side walls of the lip can be located at any location between the front of the bucket and the rear of the bucket.

Angle (2) results from a plane (3) between the rear edge of the additional side and rear wall portion (4) and the front, top of the bucket lip (5). The value of this angle is determined by the bucket hanging at a certain angle to horizontal (due to gravity) with a slurry/mud/sludge type material inside. Details of this are discussed below conjunction with FIG. 4. In the example shown in FIGS. 1-3, the rear wall of the additional side and rear wall portion (6) does not follow the plane of the existing rear wall of the bucket but is angled forward, off the vertical plane, with angle (7), relative to the bucket floor. This forward angle (7) of the additional side and rear wall portion is so that the bucket can pivot at the trunnions (8) and still clear the hoist chains or spreader bar, which is situated between the two hoist chains. The additional side walls portion are also angled inwards towards the center plane of the bucket with an angle (9) relative to the bucket floor.

The existing top rail (10) of the bucket basket can be retained in the bucket structural configuration (which may beneficially provide additional structural support) and a secondary top rail (11) should be made in the additional side and rear wall portion. This secondary top rail (11) can provide structural rigidity to the additional side and rear wall portion as well as prevent the additional side and rear wall portion from being damaged by the rigging should the rigging accidentally be dropped on the bucket. It will be appreciated that an implementation can include the secondary top rail or not. Also, the dragline bucket can include its own top rail at the section where the lip is placed or not include a separate top rail.

FIG. 4 shows how sludge/mud/slurry type material will fill the bucket to a plane—known as the sludge line (3)—if the bucket carry angle is set correctly to optimize the amount of volume of a slurry/mud/sludge type material in the basket.

FIG. 5 is a diagram showing a front perspective view of an example angled lip 502 on a tapered bucket 500 in accordance with some implementations.

FIG. 6 is a diagram showing a side elevation view of an example angled lip 602 on a tapered bucket 600 in accordance with some implementations.

FIG. 7 is a diagram showing a front elevation view of an example angled lip 702 on a tapered bucket 700 in accordance with some implementations.

FIG. 8 is a diagram showing a front perspective view of an example vertical lip 802 on a tapered bucket 800 in accordance with some implementations.

FIG. 9 is a diagram showing a side elevation view of an example vertical lip 902 on a tapered bucket 900 in accordance with some implementations.

FIG. 10 is a diagram showing a front elevation view of an example vertical lip 1002 on a tapered bucket 1000 in accordance with some implementations.

FIG. 11 is a diagram showing an exploded view of an example lip and bucket in accordance with some implementations.

FIG. 12 is a diagram showing a rear perspective view of an example lip in accordance with some implementations. Also shown in FIG. 12, the lip includes stiffening members disposed on the rear wall of the lip.

FIG. 13 is a diagram showing a front perspective view of an example lip in accordance with some implementations.

FIG. 14 is a diagram showing an exploded view of an example lip and bucket in accordance with some implementations.

FIG. 15 is a diagram showing a front perspective view of an example lip in accordance with some implementations.

FIG. 16 is a diagram showing a rear perspective view of an example lip in accordance with some implementations.

FIG. 17 is a flowchart showing an example method of manufacturing a lip for slurry-type material in accordance with some implementations. The method begins with optionally creating engineering drawings, procedures, and specifications.

Next, the method includes profile cutting (or otherwise fabricating) the steel parts for the top rail and skin plates (e.g., one or more of sidewalls and rear wall).

Next, the method includes bending applicable steel parts.

Next, the method includes fitting the top rail to the skin plates.

Next, the method includes welding (or otherwise attaching) the steel parts together (e.g., connecting the top rail to the skin plates).

Finally, the method includes optionally cleaning, grinding, and painting the lip.

It will be appreciated that one or more steps may be omitted and that the steps may be performed in a different order where appropriate and practical.

FIG. 18 is a flowchart showing an example method of manufacturing a dragline bucket including a lip for slurry-type material in accordance with some implementations. The method begins with optionally designing and engineering a dragline bucket with a soup lip.

Next, the method includes optionally creating engineering drawings.

Next, the method includes optionally creating procedures and specifications.

Next, the method includes profile cutting (or otherwise fabricating) the steel parts of the dragline bucket and soup lip.

Next, the method includes bending the applicable steel parts and procuring (or making) any necessary cast parts.

Next, the method includes fitting and welding the front ring.

Next, the method includes fitting and welding the basket.

Next, the method includes fitting and welding the front ring to the basket.

Next, the method includes fitting and welding the extra parts such as wear elements and shrouds, arch anchor brackets, and the soup lip on the top rail.

Next, the method includes optionally cleaning, grinding, and painting.

It will be appreciated that one or more steps may be omitted and that the steps may be performed in a different order where appropriate and practical.

FIG. 19 is a flowchart showing an example method of retrofitting a conventional dragline bucket with a lip for slurry-type material in accordance with some implementations. The method begins with optionally designing and engineering a soup lip to fit an existing conventional dragline bucket.

Next, the method includes optionally creating engineering drawings, procedures, and specifications.

Next, the method includes manufacturing the soup lip (e.g., according to the method shown in FIG. 17 and described above).

Next, the method includes optionally cleaning and grinding the bucket top rail.

Next, the method includes fitting and welding (or otherwise attaching) the soup lip to the top rail of the bucket.

Finally, the method includes optionally grinding, cleaning, and painting.

It will be appreciated that one or more steps may be omitted and that the steps may be performed in a different order where appropriate and practical.

While some example implementations have been described in terms of one or more embodiments with one or more example modifications, it is recognized that other modifications and variations of the embodiments described above are within the spirit and scope of the disclosed subject matter. Applicant intends to embrace any and all such modifications, variations and embodiments. 

What is claimed is:
 1. A dragline bucket comprising: a basket having a front ring, a rear wall, a first sidewall, a second sidewall, and a basket floor, wherein the first sidewall and the second sidewall each include a trunnion; a first additional side wall and a second additional side wall extending from a top rail of the basket toward a rear end of the basket at a first angle; and an additional rear wall portion at the rear end of the basket joining the first additional side wall and the second additional side wall, wherein the additional rear wall portion slopes forward at a second angle relative to the basket floor.
 2. The dragline bucket of claim 1, wherein the first additional side wall and the second additional side wall slope upwards from the top rail starting at points approximately above respective trunnions and extend upwards at an angle approximately between 20° and 40° relative to the floor towards the rear wall.
 3. The dragline bucket of claim 1, wherein the rear wall follows a first plane, and the additional rear wall portion follows a second plane different than the first plane, and wherein the additional rear wall portion slopes forward toward the front ring at an angle of approximately 45° to 60° relative to the floor so as to clear a rigging spreader bar.
 4. The dragline bucket of claim 3, wherein the first side wall and the second side wall follow a third plane and the first additional side wall, and the second additional side wall follow fourth and fifth planes, respectively, wherein the fourth and fifth planes are different than the third plane, and wherein reach of the fourth and fifth planes are inclined inward towards a longitudinal center plane of the basket at an angle of approximately 50° to 80° relative to the floor.
 5. The dragline bucket of claim 1, wherein the front ring includes an angled lip, and wherein a sludge line of the dragline bucket is defined by a plane containing the first angle of the first and second additional side wall portions and the angled lip, and wherein the sludge line forms a level line of slurry-type material inside the basket when the dragline bucket is oriented at a given angle relative to horizontal and with the angled lip being at a same vertical height as a rear edge of the additional side and rear wall portions of the basket.
 6. A lip for a dragline bucket, the lip comprising: a first side wall having a top edge angled relative to a horizontal plane including a bottom edge of the first side wall; a second side wall having a top edge angled relative to a horizontal plane including a bottom edge of the second side wall; and a rear wall joining the first side wall and the second side wall and having a top edge.
 7. The lip of claim 6, further comprising a top rail disposed at and extending along at least a portion of the top edge of the first side wall, the top edge of the second side wall, and the top edge of the rear wall.
 8. The lip of claim 6, wherein the rear wall slopes forward at an angle relative to the horizontal plane including the bottom edges of the first side wall and the second side wall.
 9. The lip of claim 6, wherein the rear wall is oriented vertically with respect to a horizontal plane including the bottom edges of the first side wall and the second side wall.
 10. The lip of claim 6, wherein the lip is constructed to be retrofitted onto a non-tapered dragline bucket.
 11. The lip of claim 6, wherein the lip is constructed to be retrofitted onto a tapered dragline bucket.
 12. The lip of claim 6, wherein the lip is constructed to be formed onto a new non-tapered dragline bucket.
 13. The lip of claim 6, wherein the lip is constructed to be formed onto a new tapered dragline bucket.
 14. A retrofit kit for a dragline bucket, the retrofit kit comprising: a lip for the dragline bucket, the lip comprising: a first side wall having a top edge angled relative to a horizontal plane including a bottom edge of the first side wall; a second side wall having a top edge angled relative to a horizontal plane including a bottom edge of the second side wall; and a rear wall joining the first side wall and the second side wall and having a top edge.
 15. The retrofit kit of claim 14, wherein the lip further comprises a top rail disposed at and extending along at least a portion of the top edge of the first side wall, the top edge of the second side wall, and the top edge of the rear wall.
 16. The retrofit kit of claim 14, wherein the rear wall slopes forward at an angle relative to the horizontal plane including the bottom edges of the first side wall and the second side wall.
 17. The retrofit kit of claim 14, wherein the rear wall is oriented vertically with respect to a horizontal plane including the bottom edges of the first side wall and the second side wall.
 18. The retrofit kit of claim 14, wherein the lip is constructed to be retrofitted onto a non-tapered dragline bucket.
 19. The retrofit kit of claim 14, wherein the lip is constructed to be retrofitted onto a tapered dragline bucket. 